1. Field of the Invention
The invention pertains to the field of pallets. More particularly, the invention pertains to metal pallets for packaging rubber blocks.
2. Description of Related Art
Wooden crates and wooden pallet bases have traditionally been used to package rubber blocks. In shrinkwrapped packaging, rubber bales are arranged and placed on the wooden pallet base (platform) and are pressed down to a pre-set level with the aid of a metal plunger and a metal performer. When the bale consolidation is completed, a polythene shrink film is placed over the rubber extending down to the upper portion of the pallet base. The pallet is held together tightly by the polythene shrink film. However, there are many problems associated with timber base packaging including contamination by wooden splinters. Also, the increasing cost of wooden pallets due to a shortage of timber in producing countries makes it difficult to obtain timber to build the pallet. The most serious problem lies in the disposal of pallet timber, which has become increasingly costly. This problem mainly affects consumers in developed countries. While wooden pallets allow stacking, they are difficult to nest. Height is a critical factor in determining the number of pallets that can be loaded into a 20-foot container for a return journey, and wooden pallets are not cost efficient for a return journey.
There have been a number of pallets patented in the past.
U.S. Pat. No. 3,167,341, xe2x80x9cNESTABLE SHIPPING PALLETSxe2x80x9d, Higgins (1965), describes a metal nesting pallet. The pallet does not have hinge supports.
U.S. Pat. No. 3,433,184, xe2x80x9cNESTABLE PALLETSxe2x80x9d, Addy (1969), shows a molded plastic pallet capable of nesting. The pallet does not have hinge supports.
U.S. Pat. No. 3,680,495, xe2x80x9cPALLET STRUCTURExe2x80x9d, Pike (1972), describes a pallet structure in the form of a grid, with feet extending below to make room for lift truck forks. The pallets can nest by putting the feet of an overlying pallet into the feet of a lower one. The pallet is made of plastic and does not have hinge supports.
U.S. Pat. No. 3,847,546, xe2x80x9cCONVERTIBLE CONTAINER-PALLETxe2x80x9d, Sanders et al (1975), presents a plastic pallet with low side walls that hinge into the base. When the walls are up, the pallet forms a stacking container and when the walls are down, it is a flat pallet.
U.S. Pat. No. 4,674,647, xe2x80x9cCOLLAPSIBLE STORAGE BINxe2x80x9d, Gyenge et al. (1987), describes a pallet type container made of molded plastic. The pallet nests when stacked in the erected or collapsed mode. The side and end walls of the container pivot to the pallet base means of integrally molded snap-fitting hinges.
In addition, the Malaysian Rubber Board (MRB) has developed a metal pallet that allows nesting but not stacking. This pallet has more than four legs in various positions and a wire mesh platform. The pallet also has a metal strip border that runs along the side of the rectangular tube framework. The nesting height (dead height) between two pallets is made up of the height of the metal strip and the height of the rectangular tube framework. A major drawback of this design is a narrow nesting gap between nested pallets. This creates a major problem if one tries to retrieve an empty pallet. One has to start from the very top pallet because there are no other means to retrieve these pallets, except perhaps by introducing a hook retrieval method. However, there is no apparatus such as hook holes, half moon rings, or O-rings on the pallet to allow for retrieval via hooks. Also, the dead height limits the number of pallets that can be loaded in a 20-foot container for a return journey, thereby resulting in a higher transportation cost per pallet unit. Another drawback relates to the nesting of empty pallets. Although there is no problem when empty pallets are nested manually to chest height (about 20 pallets), a problem arises when one tries to nest 45 pallets in single stack. A single stack of 45 pallets is equivalent to the height of a 20-foot container. Also, the Malaysian Rubber Board pallet was not designed for forklift truck operation. The flimsy flat metal strip border is easily damaged by the force of a forklift truck blade. In addition, the wire mesh platform requires additional packaging materials such as a piece of cardboard or a thick polythene sheet on top of the wire mesh to prevent the rubber from falling out of the large square openings.
Therefore, there is a need in the art for a recyclable nesting and stacking pallet for the transportation of rubber blocks.
The preceding and other shortcomings of the prior art are addressed and overcome by the present invention. A pallet for stacking and nesting includes a plurality of hinged flip members and an angular bar member that conceals the rectangular tube framework. The pallet is preferably used to transport rubber blocks. Alternatively, it is used for bulk transport of any non-perishable cargo. The hinge contributes to the easy nesting and stacking process. In addition, the angular bar member on top of the rectangular framework serves as a border to conceal the height of the rectangular tube and thus maximize the return of pallets. The novel pallet allows both nesting and stacking and ensures the maximization of the returning pallet.
In a preferred embodiment, the pallet includes a plurality of hinges having a flip member which is easily rotated by hand between a first unextended position and a second extended position. When the flip member is flipped into the unextended position, it uncovers a cavity a pallet leg creates. Nesting of an empty pallet is possible when the flip members are in this position. Bar members preferably serve as a guide and glide the receiving pallet to slide in position during the nesting process. The pallet is stackable when the flip members are flipped into an extended position, covering up the leg cavities. Each of the hinges acts as a foot to support members of the receiving pallet. The pallet platform is preferably made of a sheet of metal. An angular bar member is preferably attached to the rectangular framework and serves as a border for the pallet. Holes are preferably found within the angular bar member. These holes allow manual lifting of the pallet using hooks. Rings at the base of the rectangular framework preferably allow rubber blocks to be strapped across the pallet from both sides. The whole pallet is preferably galvanized for use in packaging rubber blocks.